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(11) | EP 0 266 301 A3 |
(12) | EUROPEAN PATENT APPLICATION |
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(54) | Refrigerant metering in a variable flow system |
(57) In a refrigeration system having a compressor (14) driven by a variable speed motor
(21), the refrigerant flow volume through the expansion device (25) is controlled
by way of a solenoid driven piston (36) which alternately opens and closes the orifice
(32), with the duty cycle of the solenoid (42) being controlled such that the time
period in which the orifice (32) is open is proportional to the speed of the motor
(21). A bypass channel (31) is provided in parallel around the orifice (32) such that
a minimal flow is provided to thereby share the load with the modulating orifice (32)
and act to dampen the movement of the solenoid piston (36). |